Search

Vantage point-based indexing is a popular technique for implementing range queries in main memory database. Vantage points are reference points that are used to improve the performance of range queries. In the past, vantage points have been derived from the data points in the database by using various heuristics. These approaches are, therefore, data dependent and not able to handle dynamic databases (allowing insertions and deletions) easily. Further, the amount of time needed for deriving vantage points for these approaches is very high for larger databases. We propose a data-independent technique for creating vantage points. Constraint of our approach is that values in each dimension of the feature vectors have to be bounded. Extensive experiments with real and synthetic data show that the proposed technique is superior to existing methods. [ABSTRACT FROM AUTHOR]

With advances in Next Generation Sequencing (NGS) technology, individual institutes and research consortia have publicly released large-scale accumulated genomic data obtained in various projects. NGS technology has also been rapidly adopted in clinical practice, and many governments and research organizations have established a regulatory framework and guidelines to ensure the accuracy and reliability of NGS-based testing. These guidelines are essential for the safe use of NGS-based testing, but do not provide enough details that can be specifically applied to the various applications of NGS. In the clinical setting of NGS technology, clinical laboratories should optimize the NGS workflow for their specific uses and performance should be thoroughly evaluated through numerous experiments. However, process optimization and performance evaluation are a great burden to the laboratory in terms of cost and time because of the technical characteristics of NGS technology. The Samsung Medical Center (SMC) has developed and utilized cancer panel sequencing, namely CancerSCAN, which is approved for clinical use by the Ministry of Food and Drug Safety (MFDS) in Korea. SMC has performed various experiments to optimize and evaluate the process of CancerSCAN. In this study, we developed a benchmark database for integrating and sharing these data for process optimization of cancer panel sequencing. This benchmark database contains information on data production and provides functionalities for searching, browsing, and downloading experimental data and raw data files. This benchmark database will be beneficial to researchers, laboratory staff, or potential stakeholders. Database URL: http://129.150.178.10:8080/qms/nqbp/nqbp_home.do [ABSTRACT FROM AUTHOR]

Abstract: Broadcast disk technique has been often used to disseminate frequently requested data efficiently to a large volume of mobile clients over wireless channels. In broadcast disk environments, a server often broadcasts different data items with differing frequencies to reflect the skewed data access patterns of mobile clients. Previously proposed concurrency control methods for mobile transactions in wireless broadcast environments are focused on the mobile transactions with uniform data access patterns. These protocols perform poorly in broadcast disk environments where the data access patterns of mobile transactions are skewed. In broadcast disk environments, the time length of a broadcast cycle usually becomes large to reflect the skewed data access patterns. This will often cause read-only transactions to access old data items rather than the latest data items. Furthermore, updating mobile transactions will be frequently aborted and restarted in the final validation stage due to the update conflict of the same data items with high access frequencies. This problem will increase the average response time of the update mobile transactions and waste the uplink communication bandwidth. In this paper, we extend the existing FBOCC concurrency control method to efficiently handle mobile transactions with skewed data access patterns in broadcast disk environments. Our method allows read-only transactions to access the more updated data, and reduces the average response time of updating transactions through early aborts and restarts. Our method also reduces the amount of uplink communication bandwidth for the final validation of the update transactions. We present an in-depth experimental analysis of our method by comparing with existing concurrency control protocols. Our performance analysis shows that it significantly decreases the average response time and the amount of uplink bandwidths over existing methods. [Copyright &y& Elsevier]

Presents a theoretical and experimental approach to identify fragments based on lattice structures. Background on recursive relations in next generation databases; Fragment description; Maximal and minimal nodes approach; Heuristic approach for finding lattice cover.